/*
NPlot - A charting library for .NET

LinePlot.cs
Copyright (C) 2003
Matt Howlett

Redistribution and use of NPlot or parts there-of in source and
binary forms, with or without modification, are permitted provided
that the following conditions are met:

1. Re-distributions in source form must retain at the head of each
   source file the above copyright notice, this list of conditions
   and the following disclaimer.

2. Any product ("the product") that makes use NPlot or parts 
   there-of must either:
  
    (a) allow any user of the product to obtain a complete machine-
        readable copy of the corresponding source code for the 
        product and the version of NPlot used for a charge no more
        than your cost of physically performing source distribution,
	on a medium customarily used for software interchange, or:

    (b) reproduce the following text in the documentation, about 
        box or other materials intended to be read by human users
        of the product that is provided to every human user of the
        product: 
   
              "This product includes software developed as 
              part of the NPlot library project available 
              from: http://www.nplot.com/" 

        The words "This product" may optionally be replace with 
        the actual name of the product.

------------------------------------------------------------------------

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

using System;
using System.Drawing;
using System.Diagnostics;

namespace NPlot
{

	/// <summary>
	/// Encapsulates functionality for plotting data as a line chart.
	/// </summary>
	public class LinePlot : BaseSequencePlot, IPlot, ISequencePlot
	{

		/// <summary>
		/// Default constructor
		/// </summary>
		public LinePlot()
		{
		}


		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="dataSource">The data source to associate with this plot</param>
		public LinePlot( object dataSource )
		{
			this.DataSource = dataSource;
		}


		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="ordinateData">the ordinate data to associate with this plot.</param>
		/// <param name="abscissaData">the abscissa data to associate with this plot.</param>
		public LinePlot( object ordinateData, object abscissaData )
		{
			this.OrdinateData = ordinateData;
			this.AbscissaData = abscissaData;
		}


		/// <summary>
		/// Draws the line plot on a GDI+ surface against the provided x and y axes.
		/// </summary>
		/// <param name="g">The GDI+ surface on which to draw.</param>
		/// <param name="xAxis">The X-Axis to draw against.</param>
		/// <param name="yAxis">The Y-Axis to draw against.</param>
		/// <param name="drawShadow">If true draw the shadow for the line. If false, draw line.</param>
		public void DrawLineOrShadow( Graphics g, PhysicalAxis xAxis, PhysicalAxis yAxis, bool drawShadow )
		{
			Pen shadowPen = null;
			if (drawShadow)
			{
				shadowPen = (Pen)this.Pen.Clone();
				shadowPen.Color = this.ShadowColor;
			}

			SequenceAdapter data = 
				new SequenceAdapter( this.DataSource, this.DataMember, this.OrdinateData, this.AbscissaData );

			ITransform2D t = Transform2D.GetTransformer( xAxis, yAxis );
			
			int numberPoints = data.Count;
			
			if (data.Count == 0)
			{
				return;
			}

			// clipping is now handled assigning a clip region in the
			// graphic object before this call
			if (numberPoints == 1)
			{
				PointF physical = t.Transform( data[0] );
				
				if (drawShadow)
				{
					g.DrawLine( shadowPen, 
						physical.X - 0.5f + this.ShadowOffset.X,
						physical.Y + this.ShadowOffset.Y,
						physical.X + 0.5f + this.ShadowOffset.X,
						physical.Y + this.ShadowOffset.Y );
				}
				else
				{
					g.DrawLine( Pen, physical.X-0.5f, physical.Y, physical.X+0.5f, physical.Y);
				}
			}
			else
			{

                // prepare for clipping
                double leftCutoff = xAxis.PhysicalToWorld(xAxis.PhysicalMin, false);
                double rightCutoff = xAxis.PhysicalToWorld(xAxis.PhysicalMax, false);
				if (leftCutoff > rightCutoff)
				{
					Utils.Swap(ref leftCutoff, ref rightCutoff);
				}
				if (drawShadow)
                {
                    // correct cut-offs
                    double shadowCorrection =
                        xAxis.PhysicalToWorld(ShadowOffset, false) - xAxis.PhysicalToWorld(new Point(0,0), false);
                    leftCutoff -= shadowCorrection;
                    rightCutoff -= shadowCorrection;
                }

                for (int i = 1; i < numberPoints; ++i)
				{
					// check to see if any values null. If so, then continue.
					double dx1 = data[i-1].X;
					double dx2 = data[i].X;
					double dy1 = data[i-1].Y;
					double dy2 = data[i].Y;
					if ( Double.IsNaN(dx1) || Double.IsNaN(dy1) ||
						Double.IsNaN(dx2) || Double.IsNaN(dy2) )
					{
						continue;
					}

                    // do horizontal clipping here, to speed up
                    if ((dx1 < leftCutoff || rightCutoff < dx1) &&
                        (dx2 < leftCutoff || rightCutoff < dx2))
                    {
                        continue;
                    }

					// else draw line.
					PointF p1 = t.Transform( data[i-1] );
					PointF p2 = t.Transform( data[i] );
                    
                    // when very far zoomed in, points can fall ontop of each other,
                    // and g.DrawLine throws an overflow exception
                    if (p1.Equals(p2))
                        continue;

					if (drawShadow)
					{
						g.DrawLine( shadowPen, 
							p1.X + ShadowOffset.X,
							p1.Y + ShadowOffset.Y,
							p2.X + ShadowOffset.X,
							p2.Y + ShadowOffset.Y );
					}
					else
					{
						g.DrawLine( Pen, p1.X, p1.Y, p2.X, p2.Y );
					}
				}
			}

		}


		/// <summary>
		/// Draws the line plot on a GDI+ surface against the provided x and y axes.
		/// </summary>
		/// <param name="g">The GDI+ surface on which to draw.</param>
		/// <param name="xAxis">The X-Axis to draw against.</param>
		/// <param name="yAxis">The Y-Axis to draw against.</param>
		public void Draw( Graphics g, PhysicalAxis xAxis, PhysicalAxis yAxis )
		{
			if (this.shadow_)
			{
				this.DrawLineOrShadow( g, xAxis, yAxis, true );
			}

			this.DrawLineOrShadow( g, xAxis, yAxis, false );
		}


		/// <summary>
		/// Returns an x-axis that is suitable for drawing this plot.
		/// </summary>
		/// <returns>A suitable x-axis.</returns>
		public Axis SuggestXAxis()
		{
			SequenceAdapter data_ = 
				new SequenceAdapter( this.DataSource, this.DataMember, this.OrdinateData, this.AbscissaData );

			return data_.SuggestXAxis();
		}


		/// <summary>
		/// Returns a y-axis that is suitable for drawing this plot.
		/// </summary>
		/// <returns>A suitable y-axis.</returns>
		public Axis SuggestYAxis()
		{
			SequenceAdapter data_ = 
				new SequenceAdapter( this.DataSource, this.DataMember, this.OrdinateData, this.AbscissaData );

			return data_.SuggestYAxis();
		}


		/// <summary>
		/// If true, draw a shadow under the line.
		/// </summary>
		public bool Shadow
		{
			get
			{
				return shadow_;
			}
			set
			{
				shadow_ = value;
			}
		}
		private bool shadow_ = false;
	

		/// <summary>
		/// Color of line shadow if drawn. Use Shadow method to turn shadow on and off.
		/// </summary>
		public Color ShadowColor
		{
			get
			{
				return shadowColor_;
			}
			set
			{
				shadowColor_ = value;
			}
		}
		private Color shadowColor_ = Color.FromArgb(100,100,100);


		/// <summary>
		/// Offset of shadow line from primary line.
		/// </summary>
		public Point ShadowOffset
		{
			get
			{
				return shadowOffset_;
			}
			set
			{
				shadowOffset_ = value;
			}
		}
		private Point shadowOffset_ = new Point( 1, 1 );


        /// <summary>
        /// Draws a representation of this plot in the legend.
        /// </summary>
        /// <param name="g">The graphics surface on which to draw.</param>
        /// <param name="startEnd">A rectangle specifying the bounds of the area in the legend set aside for drawing.</param>
        public virtual void DrawInLegend(Graphics g, Rectangle startEnd)
        {
            g.DrawLine(pen_, startEnd.Left, (startEnd.Top + startEnd.Bottom) / 2,
                startEnd.Right, (startEnd.Top + startEnd.Bottom) / 2);
        }


        /// <summary>
        /// The pen used to draw the plot
        /// </summary>
        public System.Drawing.Pen Pen
        {
            get
            {
                return pen_;
            }
            set
            {
                pen_ = value;
            }
        }
        private System.Drawing.Pen pen_ = new Pen(Color.Black);


        /// <summary>
        /// The color of the pen used to draw lines in this plot.
        /// </summary>
        public System.Drawing.Color Color
        {
            set
            {
                if (pen_ != null)
                {
                    pen_.Color = value;
                }
                else
                {
                    pen_ = new Pen(value);
                }
            }
            get
            {
                return pen_.Color;
            }
        }

    
    }
}
